1. Field of the Invention
This invention relates generally to switches, and particularly to a time delay switch using the resistance of a liquid to effect a time delay.
2. Description of the Prior Art
It is frequently desirable to control the operation of electrical devices, such as lighting systems, by means of switches which operate on a predetermined time delay. Some of the known switches for this purpose, such as that shown in U.S. Pat. No. 3,020,363, issued Feb. 6, 1962, to J. T. Gurney, Sr., utilize mechanical rather than thermal or electrical time delay means in order to obtain the desired time delay interval. Further, many prior art devices use gravity operated mechanisms in order to realize a time delay function, with examples of these latter devices being found in U.S. Pat. Nos. 1,817,806, issued Aug. 4, 1931, to R. D. Delamere; 2,209,253, issued July 23, 1940, to W. C. Strungart; 2,437,197, issued Mar. 2, 1948, to C. B. Ivester; and 2,755,349, issued July 17, 1956, to C. H. Silvers.